Alarm for glue-heaters.



, C. H. NIEMANN.

ALARM FOR GLUB HEATERS.

APPLIOATIOH FILED 0011, 190e.

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Patented May 1 7, 1 9 10.

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UNITED STATES PATENT OFFICE.

cLEMENs II. NIEMANN, or CINCINNATI, oIIIo.

.ALARM FOR GLUE-HEATERS.

To all whom 'it may concern:

Be it known that I, CLEMENS H. NIE- MANN, a citizen of the UnitedStates, residing at Cincinnati, in the county of I-Iamilton and State ofOhio, have invented certain new and useful Improvements in Alarms forGlue-Heaters, of which the following is a specification.

Glue, such as generally used by carpenters, joiners, wood workers andother trades, usually made from animal tissue, will become plastic orsoft by the application of heat and sets upon cooling, and is usuallycooked before use and applied in a heated state. If, however, too greata degree of heat be applied to the glue, it will deteriorate and itsadhesive qualities will be lessened or destroyed. If, on the other hand,too low a degree of heat be applied to the glue, it will not meltproperly or be of the correct consistency when applied. The consistencyof the glue depends also not only upon the heat of the glue, but alsoupon the proper amount of water or moisture added to the glue incooking. If the degree of heat applied in cooking be too low, there isdanger that the workman will add too much water in order to bring themixture to the proper liquid state for ready application, as with abrush, and it is the object of my invention, therefore, to provide meansfor indicating the heat of the glue, so that the glue may be maintainedat the proper heat.

My invention consists in providing an alarm for a glue-heater which willindicate when the limits of heat within which it is desired to maintainthe glue are reached, and the invention will be readily understood fromthe following description and claims, and from the drawing in whichlatter:

Figure 1 is a side elevation of my improved device, the glue-tank beingpartly broken away for better illustration of parts. Fig. 2 is a frontelevation of my improved device. Fig. 3 is a cross-section of the sametaken on the line 3-3 of Fig. 2, with the fingers shown in sideelevation in somewhat different relation from that shown in Fig. 2; and,Fig. 1 is a detail in cross-section showing the manner of attaching thegluefaucet.

1 represents a glue-tank comprising an inner shell 2 and an outer shell3 forming a jacketed tank which has a compartment 4 between the shellsfor receiving steam or hot Specication of Letters Patent.

Application filed October 1, 1906.

Patented May 17, 1910.

Serial No. 336,984.

water for heating the glue, which latter is received by the inner shell.The inner shell is preferably removable from the outer shell.

5 is an inlet pipe and 6 is an outlet pipe for steam or hot water,communicating with the compartment 4L and respectively having valves 7 8therein. The pipe 5 may also serve as an inlet pipe when hot water isemployed for heating the tank, and the compartment may also have anexhaust pipe 9 communicating therewith, which however is closed by a cap10 when steam under pressure is used to heat the glue. A water-gage 11having a glass gage-tube 12 may also communicate with the compartment 4.A faucet 18 communicates with the inner shell for discharging the glue.For permitting removal of the faucet when removing the inner shell, thefaucet may have securing means somewhat similar to the means providedand hereinafter described for securing the thermometer-thimble in place.Thus 14 is a ferrule secured to the outer case and extending inwardly.The inner end of this ferrule abuts against the outer face of the innershell. The ferrule is internally threaded and receives the threaded tube15 of the faucet. A nut 16 screws over the inner end of this threadedtube and clamps the inner shell against the inner end of the ferrule 14.The tank may also be provided with a lid 17. The heating may also beaccomplished by a flame under the tank.

21 is an indicator-case.

22 is an indicator-finger for indicating the temperature of the glue.This finger is secured to a shaft 23. The shaft 23 is actuated by ausual construction of thermometer which may for instance comprise athermal spring 24 extending into a bulb 25 in ordinary and well-knownmanner.

In order to cause the heated glue to make contact with the bulb 25 forindicating the true temperature of the glue and to separate the bulbfrom the direct influence of the heat of the heating agency, and at thesame time to place the bulb in such position that it will be out of thereach of the paddle or other stirrer that may be used to stir the glue,I provide the peculiar mounting for the temperature indicator shown anddescribed.

26 is a ferrule rigidly secured to the outer shell and having an innerabutting end 27. This ferrule has an internally threaded bore.

A hollow cap 29 externally threaded as shown at 30, screws into thisferrule and takes through openings respectively in the outer and innershells. A nut 35 screws over the inner end of the cap and securelyclamps the outer face of the inner shell against the inner abutting end2T of t-he ferrule. This construction prevents leakage of the heatingagency and leakage of the glue into the heating compartment. A tightjoint may be thus secured, especially as in practice the ferrule may beof iron and the inner shell of a softer metal or composition, as copperor brass. The cap has an outer head 34, which may take the form of abolthead. The head has an internally threaded bore for receiving thethreaded stud 3G of the thermometer case.

There is an insulated connection 4l in the shaft 23 for electricallyinsulating the finger 22 from the parts in rear of the shaft. A collar42 takes about the shaft, the latter being journaled in said collar, andan electric connection 43 connects said collar with a binding-post 44 onthe case 2l. The shaft 23 is journaled in an insulating bearing 45.

46 is a contact-finger which has a hub 47 journaled about the insulatingbearing 45. A collar 48 takes about this hub and an electric connection49 connects said lastnamed collar with a binding-post 50 on the case 2l.

5l is a second contact-finger journaled on the hub 47. The hub 47 makescontact with the collar 48.

52 is the face-plate of the indicator, an insulated bearing 53insulating the faceplate from the contact-fingers and the collar 48. Theinsulated bearing 45 extends between the collars 42 4S and between thecontact-fingers and the indicator-finger. This construction insulatesthe indicatorfinger from the contact-fingers, except when making contacttherewith and acting as electric terminals as hereinafter explained, andalso insulates said fingers from the case, and electrically connects theindicator-finger with the binding-post 44, and further electricallyconnects said contact-fingers with the binding-post 50. Thecontact-fingers are respectively provided with contact-stems 54 55 withwhich the indicator-finger is adapted to engage when the glue becomesexcessively heated or drops to a heat below the desired normal. Thebinding-posts are electrically connected with an alarm shown as a bell56 and with a source of electric energy shown as a battery 57 as byconductors 5S 59 GO. The markings on the face-plate represent degrees ofheat.

I provide means for shifting the contactfingers, so that the alarm maybe set for any desired range in degrees of heat it may be desired toapply to the glue. Thus 6l is the glass-front of the indicator-case.

(32 is a shifting-linger having a lug G3 adapted to engage the stems 5455 for shifting the contact-fingers. The shifter-finger is secured toashaft (34 mounted in a bearing 65 of the glass-front 6l and having aknob GG for turning the same. The shaft is slidable longitudinally inits bearing for bringing the lug (S3 within lateral range of thecontact-stems 54 55, a spring (37 normally however retracting theshifter-finger out of range of said stems. If it is desired to shift thecontact-fingers, the knob G6 is grasped and the shifting-finger isturned so as to bring its lug to either side either contactstem, and theshifting-finger is pushed inwardly, which brings it wit-hin lateralrange of the stem of the contact-finger, the shifting-finger being thenturned to bring the contact-finger to register with the desired mark onthe indicator face representing the desired upward or downward limit ofheat to which the glue is to be subjected. These limts of heat may varywith the different classes of glue, or the work to which the glue is tobe put. Thus it has been found that a heat in excess of 1(30 degreesFahrenheit will lessen the adhesive quality of the glue, and the longerthe excessive heat is maintained the greater will be the detrimentaleffect, until the adhesive qualities of the glue are practicallydestroyed, so that instant remedy is desired, and is obtained by myimproved device. The jelly, that is, the mixture of glue and water willbecome thinner as the degree of heat increases, with the result that,with the proper amount of glue for the mixture, the jelly will becometoo thin at an excessive heat, inducing the workmen to add an excessiveamount of glue to obtain a proper consistency in the jelly, andtherefore wasting glue. One contactfinger may therefore be set forinstance at 1GO degrees.

It has been found that below 140 degrees Fahrenheit the spreadingefficiency of the glue will be lessened, and the glue will not bereceived properly into the pores of the wood or other articles beingglued, resulting in poor joints. It is therefore desirable that. theglue shall not go below 140 degrees Fahrenheit, and the other contactfinger may therefore be shifted to register with the mark 140 on thedial. The heat of the glue may without detriment vary between these twopoints, but is preferably maintained as near 150 degrees Fahrenheit aspossible, and as the heatvaries the indicator-finger may shift betweenthe contact-fmgers. As soon, however, as the indicator-linger makescontact with the contact-stem on either contactfinger, electric circuitwill be formed between the battery and alarm, and the bell will ring,thereby indicating the abnormal state of the glue, which may thereuponbe forthwith remedied.

Having thus fully described my invention what I claim as new and desireto secure by Letters Patent is:

1. In combination, in a glue heater, a j acketed container comprising athimble spanning the space of the jacket thereof and interrupting Saidspace and opening into the interior of the container, with a thermometerhaving a bulb in said thimble permanently located in the saidinterruption of said space and distanced from the wall of said thimbleadjacent said opening for permitting the contents of the container' tocontact said bulb and removing said bulb from direct influence of thetemperature in said jacket, substantially as described.

2. The combination of a glue heater comprising an inner shell and anouter shell forming' a jacketed tank having a heatingcompartment betweensaid shells, a thimble l releasably connecting said shells and openinginto said inner shell, and a thermometerbulb secured in said thimble andpermanently located between the planes of said shells and distanced fromthe wall of Said thimble adjacent said heating compartment but exposedat said opening for permitting the glue in said inner shell to contactwith said bulb.

3. In a glue heater, the combination of an outer shell, an inner shellreleasably received thereby and spaced from said outer shell for forminga heatingcompartment between said shells, pipes for conveying a heatingagency secured to said outer shell, a thimble releasably connecting saidshells and provided withl a lateral wall having an opening at the innerend thereof opening into said inner shell and having a closing wall atits outer end, the said thimble forming an interruption in saidheating-compartment,

a thermometer having a bulb located within said thimble and secured insaid outer end but distanced from said lat-eral wall for removing saidbulb from direct influence of the heating agency in said heatingcompartment and permitting contact of the glue in said inner shell withsaid bulb, but removing said bulb from contact of a stirrer 1n saidinner shell, said bulb being permanently located in the saidinterruption of said heating-compartment and outside the vertical planeof the interior of said inner shell, substantially as described 4. In aglue heater, the combination of an outer shell 3, a. removable innerglue-container shell 2, said shells having a heatingcompartment 4:therebetween, a hollow cap 29 releasably secured to both of said shellsand having' a lateral wall spanning said heating-compartinent andopening into said inner shell, said hollow cap forming an interruptionin said heating-compartment, a bulb secured in said hollow cap from itsouter end and distanced from said lateral wall for removing it fromdirect influence of the heating-agency in said heating-compartment andpermitting the glue in said inner shell to be received about said bulb,said bulb being within said hollow cap for removing it from danger ofcontact by a glue stirrer in said inner shell, and permanently locatedin the said interruption of said heating-compartment, substantially asdescribed.

In testimony whereof I have subscribed my name hereto in the presence oftwo subscribing witnesses.

CLEMENS H. NIEMANN.

Witnesses Ti-Inononn C. JUNG, CORDELIA OHEARN.

